Organic Primer, ch 1, ch 2, ch3, and ch4

Organic Chem test 1 Dr. Guo. One stop studying

Which of the following is most likely to dissolve in hexane, a nonpolar organic liquid?

(cyclopentane) is soluble in hexane in all proportions. Cyclopentane and hexane are nonpolar molecules, with only dispersion forces between molecules. Each one has the same type of intermolecular attractions, whether as a pure substance or in a mixture. The other substances have intermolecular attractions (dipole−−dipole and hydrogen bonds for the molecules; ionic bonds in the case ofKBrKBr) that aren’t in effect when mixed with hexane.

What are the intermolecular forces between molecules in a liquid sample of sulfur trioxide, SO3?

dispersion force

No hydrogen bonding capability?

• CH₂=CH₂

• CH₃CH₂CH₃

Can be a hyddrogen bond acceptor but not a donor

• N(CH₃)₂

• CH₃C(O)CH₃

• CH₃OCH₃

Can be a hydrogen bond acceptor and donor

• H₂O

• CH₃OH

• CH₃CH₂NH₂

Rank this highest to lowest bowling point? CH3CH3, CH3CH2CH3, CH3CH2CH2CH3, CH3CH(CH3)2

CH₃CH₂CH₂CH₃ (butane) > CH₃CH(CH₃)₂ (isobutane) > CH₃CH₂CH₃ (propane) > CH₃CH₃ (ethane)

Polar or non polar? NH3, H2, CO2, CH4, HBr, BF3

Polar: NH3, HBr

Non Polar: H2, CO2, CH4, BF3

Choose the best description for the indicated bond.

This is a triple bond between two carbons in which a sigma bond arises from sp−spsp−sp overlap and two pi bonds are formed by side-to-side overlap of unhybridized pp orbitals on each carbon

The atomic number of boron is 5. The correct electronic configuration of boron is:

1s22s22p1

How many distinct p orbitals exist in the second electron shell, where n = 2?

3

The ________ tells us that each orbital can hold a maximum of 2 electrons.

Pauli exclusion principle

A node is a region of high electron density between the two atoms in a covalent bond.

False

To make it true it would be “A node is a region in an orbital where the probability of finding an electron is zero”

When filling two or more orbitals of the same energy with electrons, the electrons will go into different orbitals rather than pair up in the same orbital.

True

Atoms with the same number of protons but different numbers of neutrons are called ________.

isotopes

The electron density of ________ orbitals has spherical symmetry.

s

An oxygen atom has ________ valence electrons.

6

Which element in the second row of the periodic table has six valence electrons and a valence of two?

oxygen

Orbitals which are equal in energy are referred to as ________.

degenerate

In a carbon atom, the 2s and 2p orbitals are equal in energy.

False The 2s orbital is lower in energy than the 2p orbitals.

The element with the electronic configuration 1s²2s²2p⁶3s¹ is ________.

sodium

A carbon-hydrogen bond in ethane (CH₃CH₃) is best described a ________.

essentially nonpolar

The electronegativity of elements on the periodic table increases going ________ a column and to the ________ in each row.

up, right

Within a given row of the periodic table, electronegativity typically increases left to right across the row.

true

Which of the following molecules contains a polar covalent bond?

CH3Cl

Covalent bonds may be polar or nonpolar. What property of the atoms forming a given bond determines this?

electronegativity

The compound methylamine, CH₃NH₂, contains a C-N bond. In this bond, which of the following best describes the charge on the carbon atom?

slightly positive

The formal charge on oxygen in dimethyl ether, CH₃OCH₃, is ________.

0

For most compounds in which a nitrogen atom bears no formal charge, the valence of this nitrogen atom is ________.

3

Which of the following are correct Lewis structures, including formal charges, for nitric acid, HNO₃?

B only

Which of the following bonding patterns of carbon is not allowed in the formation of an organic compound?

f

Which of the following compounds are covalent compounds?

KCl

CF4

NH3

both KCl and CF4

both CF4 and NH3

both CF4 and NH3

When a negatively charged species is most appropriately depicted as a hybrid of several resonance forms, the negative charge present is considered to be rapidly moving between the resonance forms bearing the formal negative charge.

False
The negative charge does not literally move back and forth between resonance structures.

• Instead, the real molecule is a resonance hybrid, meaning the electron density (including the negative charge) is delocalized or spread out over the entire structure simultaneously.

• Resonance forms are just different ways of drawing the same molecule, not actual rapidly interconverting structures.

So, the charge is delocalized, not rapidly shifting between forms

When a molecule can best be represented as a series of resonance forms, each of these forms always contributes to the same degree in the hybrid.

False

Not all resonance forms contribute equally to the resonance hybrid. Some forms are more stable or significant than others, so they contribute more.

Which of the following structures (a-d) is another resonance structure

of the following organic molecule?

B

One resonance structure of a cation is shown.  Provide the other reasonable resonance structures.

Draw the important resonance forms of:

Structures ________, shown below, are resonance structures, and structure ________ is the major contributor to the overall resonance hybrid.

1,3,5:3

Draw a line-angle formula for (CH₃)₂CHCH₂CH₂NH₂.

Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default.

The Lewis structure of trimethylamine is shown below. Draw the condensed structural formula which corresponds to this Lewis structure.

(CH3)3N

The Lewis structure of pentane is shown below. Draw the condensed structural formula which corresponds to this Lewis structure.

CH3CH2CH2CH2CH3

How many carbon atoms are present in the molecule shown?

10

Which of the following condensed formulas represents the same compound as the line-angle structure shown?

CH₃CH₂OCH₂N(CH₂CH₃)₂

ndicate the line-angle structure that corresponds to the condensed structure, HOCH₂C(O)CH(CH₃)₂.

Provide the line-angle formula for the alcohol CH₃CH₂CH(OH)CH₂CH₂CH(CH₃)₂.

Provide the line-angle formula (skeletal structure) for (CH₃CH₂)₂C=O.

Provide the line-angle formula (skeletal structure) for (CH₃)₂CHCH₂CHO.

Draw an acceptable line-angle formula for cyclobutanol (shown below).

Draw an acceptable line-angle formula for the compound shown below.

Which of the following condensed formulas correctly represents the line-angle structure shown below?

(CH₃)₂CC(CH₃)CO₂H

Draw the line-angle formula for three compounds with molecular formula C₃H₈O

Provide the line-angle formula for CH₃CH₂C(CH₃)₂CH₂CHO

How many hydrogen atoms are present in the molecule shown?

18

What is the molecular formula for the molecule shown?

C7H14O

A molecule of acetylene (C₂H₂) has a ________ geometry and a molecular dipole moment that is ________.

linear, zero

Which of the following statements is correct?

A) Induced dipole interactions are usually stronger than dipole-dipole interactions

B) Polar solutes tend to be more soluble in nonpolar solvents

C) All polar molecules are capable of hydrogen bond formation

D) Higher molecular dipole values (μ) are associated with nonpolar molecules

E) The polarity of a molecule is dependent on its three-dimensional structure

E

Which one of the molecules shown below has no net molecular dipole moment?

H2C=CH2

CH2Cl2

CH2O

CH3OH

CH3Cl

H₂C=CH₂

Which one of the molecules shown below has a net molecular dipole moment?

BeCl2

CO2

CCl4

CH3CCl3

CH3CCl3

Does 1,1-dichloroethene (Cl₂C=CH₂) have a net molecular dipole moment?

Yes, 1,1-dichloroethene has a net molecular dipole moment.

Show the direction of the Cl3H molecular dipole moment in the chloroform molecule.

Which sequence ranks the following isomers in order of increasing boiling points?

3<1<2

Which of the following has the highest boiling point?

The one with the OH at the end

What intermolecular forces are present among molecules in dimethyl ether, CH₃OCH₃?

both London dispersion forces and dipole-dipole forces

Which of the molecules below can hydrogen bond to another of the same compound?

(CH₃CH₂)₂CHOH

What intermolecular attractions exist in a pure sample of methylthiol, CH₃SH?

dipole-dipole attractions

London dispersion forces

Which of the molecules below has the higher boiling point?

CH₃CH₂CH₂OH or CH₃CH₂OCH₃

CH₃CH₂CH₂OH

Which of the molecules below has the higher boiling point?
CH₃CH₂CH₂CH₂CH₃ or (CH₃)₂CHCH₂CH₃

CH₃CH₂CH₂CH₂CH3

Which of the molecules below has the higher boiling point?

(CH₃)₃N or CH₃CH₂CH₂NH₂

CH₃CH₂CH₂NH₂

The compounds below are base pairs used to form supramolecular polymers (Org. Lett. 2011, 240). They are held together by three intermolecular hydrogen bonds and each contains one intramolecular hydrogen bond. Which atom in structure B forms a hydrogen bond with the circled hydrogen in structure A?

3

Which compound is more soluble in water?
(CH₃)₂NH or CH₃CH₂CH₃

(CH₃)₂NH

Which compound is more soluble in water?
CH₃OCH₃ or CH₃CH₂OH

CH₃CH₂OH

Does the C-O bond in methanol (CH₃OH) possess an individual bond dipole moment?

Yes, the C-O bond in methanol has an individual bond dipole moment.

Draw the structure of the isomeric form of 1,2-dichloroethene (CHCl-CHCl) which has no net dipole moment.

Which functional groups below indicate the presence of two atoms connected by a triple bond?

both alkyne and nitrile

Provide the structure of an aromatic compound with seven carbon atoms.

Dopamine is shown below. What functional group, or structural element is not present in this compound?

carboxyl

Which of the following functional groups is not present in the HIV protease inhibitor drug called Saquinavir?

amine

ketone

aromatic

amide

alcohol

Ketone

Which functional group occurs more than two times in the structure of the HIV protease inhibitor drug called Saquinavir?

ketone

amine

alkene

amide

carboxylic acid

amide

Which molecule below is an alkene?

(CH3)2CHCH2NH2

(CH3)2C=CH2

CH3CH2CH2CO2H

(CH3)2CHCH2OH

CH3CH2OCH2CH3

(CH₃)₂C=CH₂

Which of the molecules below is an ester?

HC≡CCH3

CH3OCH2CH2CH3

CH3CH2CH(CH3)2

CH3COOCH3

CH3COOH

CH₃COOCH₃

Which of the functional groups below contain a hydroxyl group as a part of their structure?

aldehyde

amine

carboxylic acid

alcohol

both alcohol and carboxylic acid

both alcohol and carboxylic acid

Which of the class of organic compound below contains a carbonyl group as a part of its structure?

aldehyde

ester

carboxylic acid

ketone

all of the above

all of the above

Which of the following does not contain a carbonyl group?

carboxylic acid

ketone

aldehyde

ester

ether

ether

Anisole, the compound shown below, is an example of ________.

an ether

Acetone is a ketone that contains three carbon atoms. Provide its structure.

What is the name of the characteristic functional group found in the molecule CH₃CH₂COOH?

ester group

carboxyl group

carbonyl group

hydroxyl group

carboxyl group

Which molecule below is an ether?

CH3CH2CH2CO2H

(CH3)2CHCH2NH2

(CH3)2C=CH2

(CH3)2CHCH2OH

CH3CH2OCH2CH3

CH₃CH₂OCH₂CH₃

Which of the molecules below can be properly called an amine?

CH3COOH

CH3CH2CH2NO2

CH3CH2NHCH3

CH3CN

CH3CH2CH2OH

CH3CH2NHCH3

Which of the statements below accurately describe(s) alkanes?

Alkanes belong to the class of unsaturated hydrocarbons.

Alkanes are hydrocarbons which contain only single bonds.

Alkanes are the simplest and least reactive class of organic compounds.

Statements"Alkanes are hydrocarbons which contain only single bonds" and "Alkanes belong to the class of unsaturated hydrocarbons" are correct

Statements "Alkanes are hydrocarbons which contain only single bonds" and "Alkanes are the simplest and least reactive class of organic compounds" are correct

Statements "Alkanes are hydrocarbons which contain only single bonds" and "Alkanes are the simplest and least reactive class of organic compounds" are correct

Which of the following types of hydrocarbons is(are) saturated?

alkanes

alkenes

aromatics

alkynes

All of the above are saturated.

alkanes

If a hydrocarbon has no double or triple bonds, it is said to be ________.

saturated

If an acyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

2n + 2

How many methylene groups are present in 2,4-dimethylhexane?

2

How many secondary (2°) carbons are found in 5-ethyl-3,3,4-trimethylheptane?

3

Provide an acceptable name for (CH₃CH₂CH₂)₃CH.

4-propylheptane

Provide the name of the compound below.

3-fluoro-2,2-dimethylhexane

Provide the name of the compound below.

2,3,6,7-tetramethylnonane

Provide an acceptable name for the alkane shown below.

CH₃CH₂CH₂CH₂CH₂CH₃

Hexane

Provide an acceptable name for the alkane shown below.

2,5-dimethylheptane

Draw an acceptable structure for 3-ethyl-3-methylhexane.

Name the haloalkane shown.

3,4-dibromoheptane